Billionaire investor and Fisher Investments founder and chairman Ken Fisher told TheStreet founder Jim Cramer that he's not buying into the bitcoin craze even as some of his contemporaries pile in.

"Finance theory says you make money knowing something other people don't know," Fisher said. "And the fact of the matter is, I ask myself what I know about bitcoin that other people don't know and the answer is nothing. So, therefore, I don't need to do it."

Here's more on what these two experts are thinking as bitcoin booms.

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